Electrical devices containing a touch panel such as a personal digital assistant (PDA), a mobile phone a tablet personal computer (i.e., tablet PC) is more popular with techniques improvement. Touch panels are classified into several types and a resistive touch panel is a most representative type.
In general, a resistive touch panel refers touching the surface of the touch panel with a finger or other objects, which makes a voltage change in two contacted electrode layers inside the touch panel. The touch panel then detects the voltage change for indicating a touched position on the surface of the touch panel. As shown in FIG. 1, a touch panel comprises a first substrate 10, a spacing layer 12 and a second substrate 14. The first substrate 10 and the second substrate 14 are used to respectively detect a position along the X- and Y-axle of an input point. Multiple first electrodes 16 and second electrodes 18 are formed respectively on and between the first substrate 10 and the second substrate 14. The spacing layer 12 is tiny and dotted distributed between the first substrate 10 and the second substrate 14. While the first substrate 10 and the second substrate 14 touching each other, a particular first electrode 16 and a particular second electrode 18 form a contact that provide a short voltage for calculating the X- and Y-position of the contact.
However, the electrodes are generally either photographed in patterns by etching or formed in strips by coating and the shape of the electrode will influent the displaying performance and have drawbacks on noticeable perception for a person.
Some Exemplary Embodiments
These and other needs are addressed by the exemplary embodiments, in which one approach provided for improving displaying quality and reducing perception of color difference of a resistive touch device, which by configuring differential values of Euclidean distance and a yellow/blue differential value Δb*, or dimensions between each adjacent electrodes.
According to one aspect of an embodiment, a resistive touch device with no visual color difference comprises a first transparent conductive substrate, a second transparent conductive substrate and a spacer layer. The first transparent conductive substrate has a plurality of first transparent conductive electrodes formed on a bottom of the first transparent conductive substrate, and the each first transparent conductive electrode has a first voltage difference in a first direction. The second transparent conductive substrate has a plurality of second transparent conductive electrodes formed on a top of the second transparent conductive substrate, and the each second transparent conductive electrode has a second voltage difference in a second direction. The first direction is perpendicular to the second direction. The spacer layer is formed between the first transparent conductive substrate and the second transparent conductive substrate, which is used for isolating the first transparent conductive electrodes and the second transparent conductive electrodes.
The first transparent conductive electrodes of the first transparent conductive substrate are configured to comply with certain specifications included an optic condition, a dimensional condition or both. The optic condition defines a differential value of Euclidean distance ΔE, and the differential value of Euclidean distance ΔE can be determined according to a differential value of lightness ΔL′ a yellow/blue differential value Δb* of positions between a yellow and blue coordinates, and a red/green differential value Δa* of positions between red and green coordinates in a color space, which is provided with following relationship:ΔE=√{square root over ((ΔL)2+(Δa*)2+(Δb*)2)}
The optic condition defines the differential value of Euclidcan distance ΔE of the first transparent conductive electrode may be smaller than 5 and the yellow/blue differential value Δb* may be smaller than 1.5 when light emitted through the first transparent conductive substrate, and simultaneously defines the differential value of Euclidean distance ΔE of the first transparent conductive electrode may be smaller than 10 when light reflected from the first transparent conductive substrate. The dimensional condition defines each of the adjacent first transparent conductive electrode may have a distance of gap in a range from 50 to 1000 micro-meters.
Still other aspects, features, and advantages of the exemplary embodiments are readily apparent from the following detailed description, simply by illustrating a number of particular embodiments and implementations, including the best mode contemplated for carrying out the exemplary embodiments. The exemplary embodiments are also capable of other and different embodiments, and their several details can be modified in various obvious respects, all without departing from the spirit and scope of the exemplary embodiments. Accordingly, the drawings and description are to be regarded as illustrative, and not as restrictive.